This disclosure relates to a system and method for a solution for the INE/HO LB Bottleneck in a Worldwide Interoperability for Microwave Access (WiMAX) network.
In a WiMAX communications network, a base station (BS) may communicate with a mobile station (MS) on a communication channel. During Initial Network Entry/Handover (INE/HO), which occurs when the MS initially enters the communications network, the MS and the BS exchange initiating communications such as, for example, Subscriber Station Basic Capabilities Request (SBC-REQ) and/or Ranging Request (RNG-REQ) messages. The initiating communications may be used in order to establish the communications channel. Because the initiating communications each require transmission of data, sub-channels of the communications network are allocated to transmit the data. Thus, high demands may be imposed on a given BS of a WiMAX network, especially when high volumes of MSs attempt INE/HO (such as when multiple vehicles having WiMAX receivers or passengers with WiMAX receivers enter a WiMAX hotspot) because INE/HO requires data to be transmitted over the communications network.
Transmission of data/communications between the MS and the BS are described by a Link Budget (LB). The LB represents the gains and losses of transmission from the BS (or other transmitter) to the MS (or other receiver). System gain is a measure the Radio Frequency (RF) output of the BS and the practical limit of receiving RF output by the MS. Various factors may affect the system gain such as, for example, noisiness of a communication channel that decreases system gain and number of sub-channels used during communications (a higher number of sub-channels increases noisiness). During transmission of communications between the BS and the MS, enhanced system gain may be desirable. Various methods by which system gain is enhanced have been developed, such as, for example, Hybrid Automatic Repeat Request (HARQ).
However, while HARQ may be used for a communication channel once the MS has entered the network, HARQ is unavailable for transmission of initiating communications such as SBC-REQ and RNG-REQ during INE/HO. Thus, system gain is typically lower during conventional INE/HO as compared to when communications have already been established between the MS and the BS. As such, existing systems suffer from a LB bottleneck during INE/HO. This may lead to, for example, increased system loads as multiple MSs attempt INE/HO, which may be problematic where high volumes of MSs may enter a WiMAX communications network via a BS.
These and other drawbacks exist.